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COMMA USAGE
(http://owl.english.purdue.edu/handouts/grammar/g_comma.html)
The comma is a valuable, useful punctuation device because it separates the
structural elements of sentences into manageable segments. The rules provided here
are those found in traditional handbooks; however, in certain rhetorical contexts and
for specific purposes, these rules may be broken.
1. Use commas to separate independent clauses when they are joined by any of
these seven coordinating conjunctions: and, but, for, or, nor, so, yet.
The game was over, but the crowd refused to leave.
The student explained her question, yet the instructor still didn't seem to
understand.
Yesterday was her brother's birthday, so she took him out to dinner.
2. Use commas after introductory a) clauses, b) phrases, or c) words that come
before the main clause.
a. Common starter words for introductory clauses that should be followed by a
comma include after, although, as, because, if, since, when, while.
While I was eating, the cat scratched at the door.
Because her alarm clock was broken, she was late for class.
If you are ill, you ought to see a doctor.
When the snow stops falling, we'll shovel the driveway.
However, don't put a comma after the main clause when a dependent (subordinate)
clause follows it (except for cases of extreme contrast).
1. She was late for class, because her alarm clock was broken. (incorrect)
2. The cat scratched at the door, while I was eating. (incorrect)
3. She was still quite upset, although she had won the Oscar. (correct: extreme
contrast)
b. Common introductory phrases that should be followed by a comma include
participial and infinitive phrases, absolute phrases, nonessential appositive phrases,
and long prepositional phrases (over four words).
Having finished the test, he left the room.
To get a seat, you'd better come early.
After the test but before lunch, I went jogging.
The sun radiating intense heat, we sought shelter in the cafe.
c. Common introductory words that should be followed by a comma include yes,
however, well.
Well, perhaps he meant no harm.
Yes, the package should arrive tomorrow morning.
However, you may not be satisfied with the results.
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3. Use a pair of commas in the middle of a sentence to set off clauses, phrases, and
words that are not essential to the meaning of the sentence. Use one comma before
to indicate the beginning of the pause and one at the end to indicate the end of the
pause.
Here are some clues to help you decide whether the sentence element is essential:



If you leave out the clause, phrase, or word, does the sentence still make
sense?
Does the clause, phrase, or word interrupt the flow of words in the original
sentence?
If you move the element to a different position in the sentence, does the
sentence still make sense?
If you answer "yes" to one or more of these questions, then the element in question
is nonessential and should be set off with commas. Here are some example
sentences with nonessential elements:
Clause: That Tuesday, which happens to be my birthday, is the only day when I am
available to meet.
Phrase: This restaurant has an exciting atmosphere. The food, on the other hand, is
rather bland.
Word: I appreciate your hard work. In this case, however, you seem to have overexerted yourself.
4. Do not use commas to set off essential elements of the sentence, such as clauses
beginning with that (relative clauses). That clauses after nouns are always essential.
That clauses following a verb expressing mental action are always essential.
That clauses after nouns:
The book that I borrowed from you is excellent.
The apples that fell out of the basket are bruised.
That clauses following a verb expressing mental action:
She believes that she will be able to earn an A.
He is dreaming that he can fly.
I contend that it was wrong to mislead her.
They wished that warm weather would finally arrive.
Examples of other essential elements (no commas):
Students who cheat only harm themselves.
The baby wearing a yellow jumpsuit is my niece.
The candidate who had the least money lost the election.
Examples of nonessential elements (set off by commas):
Fred, who often cheats, is just harming himself.
My niece, wearing a yellow jumpsuit, is playing in the living room.
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The Green party candidate, who had the least money, lost the election.
Apples, which are my favorite fruit, are the main ingredient in this recipe.
Professor Benson, grinning from ear to ear, announced that the exam would be
tomorrow.
Tom, the captain of the team, was injured in the game.
It is up to you, Jane, to finish.
She was, however, too tired to make the trip.
Two hundred dollars, I think, is sufficient.
5. Use commas to separate three or more words, phrases, or clauses written in a
series.
The Constitution establishes the legislative, executive, and judicial branches of
government.
The candidate promised to lower taxes, protect the environment, reduce crime, and
end unemployment.
The prosecutor argued that the defendant, who was at the scene of the crime, who
had a strong revenge motive, and who had access to the murder weapon, was guilty
of homicide.
6. Use commas to separate two or more coordinate adjectives that describe the
same noun. Be sure never to add an extra comma between the final adjective and
the noun itself or to use commas with non-coordinate adjectives.
Coordinate adjectives are adjectives with equal ("co"-ordinate) status in describing
the noun; neither adjective is subordinate to the other. You can decide if two
adjectives in a row are coordinate by asking the following questions:

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Does the sentence make sense if the adjectives are written in reverse order?
Does the sentence make sense if the adjectives are written with and between
them?
If you answer yes to these questions, then the adjectives are coordinate and should
be separated by a comma. Here are some examples of coordinate and noncoordinate adjectives:
He was a difficult, stubborn child. (coordinate)
They lived in a white frame house. (non-coordinate)
She often wore a gray wool shawl. (non-coordinate)
Your cousin has an easy, happy smile. (coordinate)
The 1) relentless, 2) powerful 3) summer sun beat down on them. (1-2 are
coordinate; 2-3 are non-coordinate.)
The 1) relentless, 2) powerful, 3) oppressive sun beat down on them. (Both 1-2 and
2-3 are coordinate.)
7. Use a comma near the end of a sentence to separate contrasted coordinate
elements or to indicate a distinct pause or shift.
He was merely ignorant, not stupid.
The chimpanzee seemed reflective, almost human.
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You're one of the senator's close friends, aren't you?
The speaker seemed innocent, even gullible.
8. Use commas to set off phrases at the end of the sentence that refer back to the
beginning or middle of the sentence. Such phrases are free modifiers that can be
placed anywhere in the sentence without causing confusion. (If the placement of the
modifier causes confusion, then it is not "free" and must remain "bound" to the word
it modifies.)
1. Nancy waved enthusiastically at the docking ship, laughing joyously. (correct)
2a. Lisa waved at Nancy, laughing joyously. (incorrect: Who is laughing, Lisa or
Nancy?)
2b. Laughing joyously, Lisa waved at Nancy. (correct)
2c. Lisa waved at Nancy, who was laughing joyously. (correct)
9. Use commas to set off all geographical names, items in dates (except the month
and day), addresses (except the street number and name), and titles in names.
Birmingham, Alabama, gets its name from Birmingham, England.
July 22, 1959, was a momentous day in his life.
Who lives at 1600 Pennsylvania Avenue, Washington, DC?
Rachel B. Lake, MD, will be the principal speaker.
(When you use just the month and the year, no comma is necessary after the month
or year: "The average temperatures for July 1998 are the highest on record for that
month.")
10. Use a comma to shift between the main discourse and a quotation.
John said without emotion, "I'll see you tomorrow."
"I was able," she answered, "to complete the assignment."
In 1848, Marx wrote, "Workers of the world, unite!"
11. Use commas wherever necessary to prevent possible confusion or misreading.
To George, Harrison had been a sort of idol.
Comma Abuse
Commas in the wrong places can break a sentence into illogical segments or confuse
readers with unnecessary and unexpected pauses.
12. Don't use a comma to separate the subject from the verb.
An eighteen-year old in California, is now considered an adult. (incorrect)
The most important attribute of a ball player, is quick reflex actions. (incorrect)
13. Don't put a comma between the two verbs or verb phrases in a compound
predicate.
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We laid out our music and snacks, and began to study. (incorrect)
I turned the corner, and ran smack into a patrol car. (incorrect)
14. Don't put a comma between the two nouns, noun phrases, or noun clauses in a
compound subject or compound object.
The music teacher from your high school, and the football coach from mine are
married. (incorrect: compound subject)
Jeff told me that the job was still available, and that the manager wanted to
interview me. (incorrect: compound object)
15. Don't put a comma after the main clause when a dependent (subordinate) clause
follows it (except for cases of extreme contrast).
1. She was late for class, because her alarm clock was broken. (incorrect)
2. The cat scratched at the door, while I was eating. (incorrect)
3. She was still quite upset, although she had won the Oscar. (correct: extreme
contrast)
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COMMA EXERCISE 1
Add commas as needed in the sentences below. On the line to the left of each
sentence, write the number of the appropriate comma rule. If the sentence is correct
as it is, write C
1. _____He left the scene of the accident and tried to forget that it had happened.
2. _____ Oil which is lighter than water rises to the surface.
3. _____ Madame de Stael was an attractive gracious lady.
4. _____ Nice is a word with many meanings and some of them are contradictory.
5. _____ The contractor testified that the house was completed and that the work
had been done properly.
6. _____ Some people refuse to go to the zoo because of pity for creatures that
must live in small cages.
7. _____ Taxicabs that are dirty are illegal in some cities.
8. _____ The closet contained worn clothes old shoes and dirty hats.
9. _____ The uninvited guest wore a dark blue tweed suit.
10. _____ After surviving this ordeal the trapper felt relieved.
11. _____ Mark Twain's early novels I believe stand the test of time.
12. _____ December 7 1941 will never be forgotten.
13. _____ The field was safe enough wasn't it?
14. _____ Write the editor of the Atlantic 8 Arlington Street Boston Massachusetts
02116.
15. _____ He replied "I have no idea what you mean."
16. _____ After a good washing and grooming the pup looked like a new dog.
17. _____ Because of their opposition to institutions that force creatures to live in
captivity some people refuse to go to the zoo.
18. _____ Men who are bald are frequently the ones who are the most authoritative
on the subject of baldness.
19. _____ Vests which were once popular have been out of vogue for several years.
20. _____ As a celestial goddess she regulated the course of the heavenly bodies and
controlled the alternating seasons.
21.
_____ I hope that some day he will learn how to be polite.